... #), Hairline,aid pickling and so onProduction technologySeamless steel pipeWelded steel pipeSurface treatmentPolishing or notThe stainless steel barstandardASTM,GBmaterial201,202,301,304,316,316L,316LN ... ,317,317L,309,309S,310,310S,430,409specificationRoundSquarerectangle 304l stainless steel tube